Implementing delayed cord clamping in premature infants.

The practice of delayed cord clamping (DCC) in premature infants has proven benefit to the neonate. In a community-based perinatal centre, the practice of DCC for more than 60 s for premature infants with gestational age of <35 weeks was identified to occur infrequently at 20% in 2013. The perinatology group in conjunction with nursery, labour and delivery, and obstetric staff sought to improve adherence to the best practice of DCC for premature infants. In an effort to achieve this goal, we developed an evidence-based clinical practice guideline, included key stakeholders in its development and provided timely feedback to delivery providers about DCC performance. The frequency of DCC for this population improved from 19.5% in 2013 to 85% in 2017. The success in improving this best practice is attributed to the involvement of the multidisciplinary team who developed the guideline, and the sustained improvement was encouraged with the continued reaffirmation of DCC goals to delivery providers.

Bacterial Spine Infections in Adults: Evaluation and Management.

Bacterial spinal infections in adults can have notable adverse consequences, including pain, neurologic deficit, spinal instability and/or deformity, or death. Numerous factors can predispose a person to spinal infection, many of which affect the immune status of the patient. These infections are typically caused by direct seeding of the spine, contiguous spread, or hematogenous spread. Infections are generally grouped based on anatomic location; they are broadly categorized as vertebral osteomyelitis, discitis, and epidural abscess. In some cases, the diagnosis may not be elucidated early without a reasonable index of suspicion. Diagnosis is based on history and physical examination, laboratory data, proper imaging, and culture. Most infections can be treated with an appropriate course of antibiotics and bracing if needed. Surgical intervention is usually reserved for infections resistant to medical management, the need for open biopsy/culture, evolving spinal instability or deformity, and neurologic deficit or deterioration.

A Strategy for Control of "Random" Copolymerization of Lactide and Glycolide: Application to Synthesis of PEG-b-PLGA Block Polymers Having Narrow Dispersity.

Poly(lactic-co-glycolic acid) (PLGA) is a biodegradable copolymer that is also acceptable for use in a variety of biomedical applications. Typically, a random PLGA polymer is synthesized in a bulk batch polymerization using a tin-based catalyst at high temperatures. This methodology results in relatively broad polydispersity indexes (PDIs) due to transesterification, and the polymer product is often discolored. We report here the use of 1,8-diazabicyclo[5.4.0]-undec-7-ene (DBU), a known, effective, and convenient organocatalyst for the ring-opening polymerization of cyclic esters, to synthesize random copolymers of lactide and glycolide. The polymerization kinetics of the homo- and copolymerizations of lactide and glycolide were explored via NMR spectroscopy. A novel strategy that employs a controlled addition of the more reactive glycolide monomer to a solution containing the lactide monomer, the poly(ethylene glycol) (PEG) macroinitiator, and DBU catalyst was developed. Using this tactic (semi-batch polymerization), we synthesized a series of block copolymers that exhibited excellent correlation of the expected and observed molecular weights and possessed narrow PDIs. We also measured the thermal properties of these block copolymers and observed trends based on the composition of the block copolymer. We also explored the need for experimental rigor in several aspects of the preparations and have identified a set of convenient reaction conditions that provide polymer products that retain the aforementioned desirable characteristics. These polymerizations proceed rapidly at room temperature and without the need for tin-based catalysts to provide PEG-b-PLGAs suitable for use in biomedical investigations.

Seasonal changes in abundance and phosphorylation status of photosynthetic proteins in eastern white pine and balsam fir.

During winter, the light-harvesting complexes of evergreen plants change function from energy-harvesting to energy-dissipating centers. The goal of our study was to monitor changes in the composition of the photosynthetic apparatus that accompany these functional changes. Seasonal changes in chlorophyll fluorescence, pigment concentration, and abundance and phosphorylation status of photosynthetic proteins in Pinus strobus L. (sun-exposed trees) and Abies balsamea (L.) P. Mill. (sun-exposed and shaded trees) were examined in the cold winter climate of Minnesota. Results indicated typical seasonal changes in chlorophyll fluorescence and pigment concentration, with sustained reduced photosystem II (PSII) efficiency during winter, accompanied by retention of zeaxanthin and antheraxanthin, and winter increases in the pool of xanthophyll cycle pigments and lutein. In sun-exposed trees, all photosynthetic proteins that were monitored decreased in relative abundance during winter, although two light-harvesting chlorophyll a/b binding proteins (Lhcb2 and Lhcb5), and the PsbS protein, were enriched in non-summer months, suggesting a role for these proteins in winter acclimation. In contrast, shaded trees maintained most of their protein throughout winter, with reductions occurring in spring. Thylakoid protein phosphorylation data suggest winter increases in the phosphorylation of a PSII core protein, PsbH, in sun-exposed trees, and increases in phosphorylation of all PSII core proteins in shaded trees.